The long range goal of this research is to develop and commercialize a novel device that provides mechanical airway support to treat obstructive sleep disordered breathing (SBD). The investigators invented and fabricated a machine that requires no electricity and promises to reduce the cost of positive airway pressure for many SDB patients. The machine stores kinetic energy from exhalation against resistance as potential energy, and converts this back to kinetic energy and continued pressure during inhalation. After exploration of many designs, a totally new and unique approach demonstrates the promise of this disruptive technology but also highlights areas of critical need for additional engineering. The work now proposed will translate a compelling theoretical opportunity into an effective prototype that can be tested with human volunteers. Several percent of adults are affected by SDB, which can lead to daytime sleepiness, impaired cognitive functioning, automobile accidents, stroke, hypertension, and heart failure. Continuous positive airway pressure (CPAP) is currently an effective but expensive treatment, and the need for an electric outlet also limits use of CPAP in some situations in the U.S., and in less developed areas of the world. The potential impact of a self-powered mechanical device is significant, as the global market for CPAP was over $2 billion in 2009, is expected to grow, and potentially could grow faster if a machine were available for the many patients and countries that cannot afford current technology. The proposed device targets at minimum the sizeable subset of SDB patients who would benefit from positive airway pressure at 5 to 12 cm of water. This Phase I application focuses on engineering and bench testing. Although appropriate expiratory PAP is already generated by the current prototype, the first aim is to optimize steady return of adequately pressurized air during inhalation. Success will be defined by extension of adequate inspiratory pressure from 65% (currently) to 100% of the duration of inspiration. Average inspiratory pressure will be at least 70% of average expiratory pressure. The second aim is to minimize pressure drops across multiple required valves that presently reduce average inspiratory pressure by 0.5 cm of water per valve. Success will be defined by a pressure drop that is less than 0.5 cm of water per valve. The third aim is to develop a mask that minimizes leaks and dead space, and provides safety valves for any excessive or negative pressure. Success will be defined by essentially zero leak in laboratory testing, and by reduction of added dead space to 20 mL or less. These aims will prove feasibility, the key objective for an SBIR Phase I grant, and produce a prototype ready for human testing in a Phase II SBIR application. This project offers substantial potential impact given the prevalence, consequences, and treatment challenges posed by SDB worldwide. The patent-pending technology to be employed is completely novel and highly innovative. The investigative team, with demonstrated expertise in respiratory biomedical innovation, sleep medicine, and commercialization, is ideally positioned to execute this project successfully.